Background Art
Space vehicle dispensers are used to deploy a plurality of satellites (typically between 4-12 satellites) into low earth orbit (LEO) during a launch vehicle (LV) mission. The dispenser provides the structural link between the satellites and the launch vehicle. Typically, there are also mounted on the dispenser various electromechanical systems, including space vehicle deployment mechanisms, ordnance, and avionics lines. In some applications, it is preferred to mount the satellites at their lower surfaces on a stable, horizontal platform, rather than along a vertical surface to a central post.
With the significant expense associated with placing a plurality of satellites into low earth orbit, it is of the utmost importance that the dispenser be constructed so as to be as lightweight as possible without sacrificing structural strength, and while being able to support a plurality of independently deployable satellites thereon. One prior dispenser approach is the "Dual Manifest using external structure." In this approach, the payload fairing is split into two payload modules: an upper module and a lower module. For example, the payload fairing may be divided into a 30 foot (9.15 meter) tall lower module and a 45 foot (13.725 meter) tall upper module. Each module has its own dispenser which includes a horizontal platform for supporting a plurality of satellites thereon. During launch vehicle ascent, the upper payload fairing is jettisoned; however, the lower payload module goes into orbit. The penalty for carrying the extra payload module weight (i.e., the weight associated with the fairing of the lower payload module) to low earth orbit is less payload which can be carried into orbit. Also, the lower payload module fairing debris stays in orbit for approximately 9-12 months, which can raise the risk of damage to one or more of the deployed satellites.
Another approach is the "Dual Manifest using an internal support structure (ISS)". With this approach a full length fairing is used to encase the dispenser. Inside the full length fairing on an inner surface thereof is a slightly smaller diameter ISS with a dispenser at the bottom and on top. The ISS length is typically less than half the full fairing length, but its typical diameter (10-15 feet or 3.05-4.58 m) still represents a significant weight relative to the total payload being carried into orbit. During launch vehicle ascent, the full fairing is jettisoned. The performance gained by jettisoning the full fairing more than offsets the added weight of the ISS, thus resulting in better launch vehicle performance than the Dual Manifest using external structure approach. The drawbacks associated with using an ISS are added structural complexity and cost, as well as additional integration and operability complexities.
It is therefore a principal object of the present invention to provide a satellite dispenser for packaging a large quantity of up to about 12 or more LEO satellites in a dual platform manner while eliminating the need for an internal or external support structure associated with the dispenser, to thereby significantly reduce the overall weight of the dispenser, to thus maximize the payload capability of the dispenser.
It is still another object of the present invention to provide a satellite dispenser that allows the jettisoning of maximum fairing weight during launch vehicle ascent.
It is yet another object of the present invention to provide a satellite dispenser capable of supporting a large number of independently deployable satellites in a manner without requiring modification to presently used separation mechanisms for deploying such satellites.
It is still another object of the present invention to provide a satellite dispenser which can be constructed without additional cost over present day satellite dispenser systems and with existing manufacturing processes.